Just as New Hampshire is at the center of the battle to win the White House, the Granite State will be consequential to the size of the House majority in 2013.

There is no Senate race on the ballot this year, but both of the state’s House seats are in play, and the contests are expected to see a flood of outside money and interest this fall. Insiders in both parties say their presidential candidate gives their House candidates a distinct edge downballot.

Presumptive GOP presidential nominee Mitt Romney has campaigned in the Granite State for nearly five years and is a former governor of neighboring Massachusetts. However, President Barack Obama won the state in 2008 by 9 points, and state Democrats continue to proudly display his image on the party website.

New Hampshire’s two Republican incumbents face rematches from 2010, which turned into a political bloodbath for Democrats because of the national GOP wave. Rep. Frank Guinta has a somewhat easier path to re-election than Rep. Charles Bass, who was swept out of Congress in the 2006 wave and then rode the tide back last cycle. But the two Members’ electoral fates may well be tied together if history repeats itself.

New Hampshire has sent two Members of the same party to Congress nearly every term for two decades. Given that historical context, it is hard to see how Republicans hold one seat while the other goes Democratic.

Still, it could happen and party operatives stress that the two races have key differences.

Democrats insist the state is trending their way and that 2010 was an anomaly. They also say the Republican-led state Legislature has overreached on social issues and the blowback will benefit Democrats Ann McLane Kuster and Carol Shea-Porter. If Democrats sweep the seats, New Hampshire will have the first all-female delegation in American history and possibly a female governor as well.

The rematch scenarios will be an interesting barometer of whether New Hampshire is trending one direction or the other.

Most, but not all, New Hampshire political insiders believe this will be the easier seat for the GOP to hold. Guinta beat then-Rep. Carol Shea-Porter by a 12-point margin in 2010, and she is a perennially weak fundraiser. Republicans insist Shea-Porter is an ideal opponent. Because she’s a former Member, they have a voting record to mine, and they say she is too liberal for the district. The demographics of the 1st are better overall for Republicans, and it did not change a great deal in redistricting.

Still, Shea-Porter has EMILY’s List behind her, and Democrats are quick to tie Guinta to the tea party — a label that has grown stale in the Northeast over the past cycle. Democrats say she has moderated her tone, has high name identification and fits the district on a local level.

Democrats seem bullish about Shea-Porter’s prospects, but the fact remains that she was never a particularly strong candidate. She was swept into and out of office during national waves.

For now, the fundamentals of the race favor Guinta. Several factors could change this, most notably if President Barack Obama is able to carry New Hampshire by a sizable margin.

Democrats have high hopes for Ann McLane Kuster — and not just for the fall. She is perceived as a “future rock star” in the party among progressives.

It was widely assumed among the party faithful that she was going to win what was then an open seat in 2010, but she came up just short because of the Republican winds that prevailed across the country. Democrats repeatedly said the strength of now-Sen. Kelly Ayotte (R) — and the fact that the 2010 Senate race was a blowout — doomed Kuster. They call Bass’ victory a fluke.

Plans for 2012 were put in motion almost as soon as the 2010 results became final, with Kuster lining up for a rematch with Bass.

Republicans acknowledge that Bass has some weaknesses. He lobbied the state Legislature to come up with a new map that made his district more friendly to Republicans, but only small changes were made. GOP insiders say he is working hard to hold onto his seat and is taking nothing for granted. They are also pleased that he has been able to keep pace of late with Kuster’s powerhouse fundraising.

Democrats will try to tie Bass to the tea party as well. Republicans say he has unquestionable moderate credentials and high name identification and is capable of holding the district. Similar to the 1st district race, the presidential campaign will also come into play, but the early strength of Kuster’s campaign is undeniable.

As it stands, this race is a Tossup, but Kuster is running an energetic and hungry campaign, and it may become clear before the fall that the rating here should shift to Leans Democratic.